Base self-destruction fuze for ordnance projectiles



1955 J. A. SUNDERMANN ETAL ,011

BASE SELF-DESTRUCTION FUZE FOR ORDNANCE PROJECTILES Filed April 4, 1952 2 Sheets-Sheet l FIGJ.

FIG. 2. A 5F I a\ 1 mm;

OWEN G. BENNETT JAMES A. SUNDERMANN INVENTORS ATTORNEYS Nov. 29, 1955 J. A. SUNDERMANN ETAL 2,725,011

BASE SELF-DESTRUCTION FUZE FOR ORDNANCE PROJECTILES Filed April 4, 1952 2 Sheets-Sheet 2 OWEN 6. BEN T7 72 JAMES A. 8U ERMA/VN M INVENTORS 1' BY /Z H6 7 069mm ATTORNEYS BASE SELF-DESTRUCTION FUZE FOR ORDNANCE PROJECTILES James A. Sundermann, Silver Spring, and Owen G. Bennett, Baltimore, Md., assignors to the United States of America as represented by the Secretary of the Navy Application April 4, 1952, Serial No. 280,508

Claims. (Cl. 102-856) This invention relates generally to artillery fuzes, and more particularly to self-destruction fuzes for destroying variable time fuzed anti-aircraft projectiles. Although the invention is shown applied to variable time fuzed projectiles, it is not limited thereto as theremay be instances where use can be made of the invention to destroy projectiles fuzed with other types of fuzes, such as the conventional time or impact fuzes, where these fuzes have failed to operate. (For purposes of clarification, the term explosive shell as used hereinafter in the specification and claims comprises a shell casing with its propelling charge, and the projectile with its explosive charge.)

In the final phases of World War II, and in the present Korean conflict manyvariable time fuzed anti-aircraft shells have been fired at enemy aircraft from Naval and shore installations. Some of the projectiles which have failed to detonate on the target have been known to burst later over nearby ships and land-based personnel with attendant casualties.

It is, therefore, the principal object of this invention to provide a fuze that will insure self-destruction of the projectile when desired as in situations like those mentioned above or optionally permit longer flight times for shore bombardment when strategic considerations permit.

Another important object of this invention is to provide a self-destruction fuze arrangement for a variable time fuzed projectile that utilizes a minimum number of moving parts and which is extremely compact.

To provide a self-destructiontype of fuze or a variable time fuzed projectile which is simple and reliable in operation, economical to manufacture, and which offers the maximum safety in handling for utilizing personnel, are other objects of this invention.

In accordance with the invention, a self-destruction fuze arrangement is provided for a proximity fuzed projectile in which the fuze can be preset for on-off positions in self-destroying or time delay. The fuze arrangement is provided with a safety unit including a springlocking, apertured turntable or disk which is eccentrically positioned in relation to a center primer cap located in the fuze and by rotation of which turntable, the firing pin plunger may be selectively positioned in registry with the primer cap.

The fuze is placed in an on-position prior to firing of the proximity fuzed projectile, and the pressure from the propellant gases, upon firing the shell, acts on this firing pin plunger and, hence, forces it to penetrate a sealing member and sets off a primer cap. This action then starts a chain of events which results in the selfdestruction of the projectile at the end of a certain predetermined time interval.

While certain features and objects of the invention are generalized above, the. objects and many of the attendant advantages will be appreciated and understood most readily from an illustration and explanation of a specific embodiment thereof, as shown in the drawings and described herein.

nited States Patent In the drawings:

Fig. 1 is a longitudinal sectional view through a fuze embodying the invention, and showing the fuze in the unarmed position;

Fig. 2 is a longitudinal sectional view through a fuze embodying the invention and showing the fuze in the armed position;

Fig. 3 is an end view of the fuze arrangement shown in Fig. 2;

Fig. 4 is a cross-section on line 4-4 of Fig. 2;

Fig. 5 is a cross-section on line 5-5 of Fig. 2; and

Fig. 6 is a cross-section of line 6-6 of Fig. 2.

Fig. 7 is a section, partly in elevation, showing the selfdestruction fuze of the invention as it would appear installed in the base of a projectile, the projectile being shown fragmentarily.

Referring now to Fig. 1 of the drawing, for a more detailed description of the invention, there is shown a preferred embodiment of a self-destruction fuze 10 incorporating the features of this invention. Fuze 10 consists of a housing having a basev 12 which contains the safety unit including a turntable or rotor 14, a primer cap 16, a powder train delay assembly 18 located directly above the primer cap 16, an arming device 20, and a booster charge arrangement 22.

The angular positioning of the turntable 14 predetermines the action of the fuze. In Fig. 3, when the arrow 24 is pointing to the off-position 26, the fuze is in an unarmed position as indicated in Fig. 1. When the turntable 14 is manually rotated by means of slot 28, it is located in an on-position or self-destruction position 30 as shown best in Fig. 2. Turntable 14 is secured into one of the two positions 26 or 30, which are separated by by a spring loaded detent 32.

In the self-destroying position 30, indicated in Fig. 2, a firing pin 34 is aligned with primer cap 16, filled with a primer 36, so that the pressure generated by the buming of the propellant or chamber pressure on firing of a projectile M (Fig. 7) containing the fuze in its base, acts through a port 38 and causes the firing pin 34 to pierce an obturation gasket 40 and strike the primer cap 16. Obturation gasket 40 is usually made of rubber, although not necessarily limited thereto. Neoprene and silicone can be utilized. This gasket 40 serves the function of a sealing closure when the fuze 10 is in the offposition 26.

Primer cap 16 is located below and in communication with an expansion chamber 42. The explosion eifect of the primer 36 is communicated to igniter powder 44 formed in a lead-in passageway 45 to the powder delay assembly 18, and thus ignites the igniter powder 44.

Igniter powder 44, in turn, is in communication with a gasless delay powder train contained in an interrupted circular groove 48, and thus ignites the powder train 46. The length of time of burning of this powder train 46 depends upon the over-all actual length of the powder train and the type of powder used in the train 46. In general, however, it can vary from approximately zero seconds upwards.

At the end of the burning of powder train 46, the latter ignites an azide detonator 50 contained in a container 51 the center of the powder train delay assembly 18 through a small quantity of flash powder in an orifice 49. Detonator 50 blows through a thin lead gasket disk 52, and a thinned section 53 of a steel closure disk 54 located between detonator 50 and the main safety device 20, into the safety device section 20.

Arming device 20 comprises two overlapping rotors 56 and 58 which are mounted for rotation on shafts 60 and 62 contained in arming device 20. Each of these rotors 56 and 58 carries an explosive pellet 64 and 66, respectively. In the initial period of flight, these rotors 56 and 58, under the influence of centrifugal force revolve in relation to the arming device 20, aligning the explosive pellets 64 and 66 with the azide detonator 50 of the powder train delay assembly 18. Consequently, when detonator 50 blows into the arming device 20, the explosive wave is propagated by means of the explosive pellets 64 and 66.

A tetryl booster charge 22 located in a booster container 68 is then ignited by pellets 64 and 66, and booster charge 22, in turn, ignites the main explosive charge of the projectile M and thus accomplishes the self-destruction of the projectile.

In the OE-position or unarmed position shown in Fig. 1, the firing pin piston or plunger 34 is disaligned from the primer cap 16. Firing pressure on the turntable 14 compresses the rubber obturation gasket 49. A cavity 70 is aligned with the primer cap 16 to relieve pressure on the primer 36 due to rubber flow. Thus, the 7 primer cannot be activated, and the explosive chain leading to self-destruction of the projection is not initiated.

Although the operation of the fuze 10 has been previously described in connection with the description of the structure of fuze 10, it is believed that a concise description of the operation of the fuze as used in a projectile will be helpful.

Fuze 10 is threaded at the upper portion 72 of the housing or base 12 so that it can be screwed into a projectile, for example, of the anti-aircraft type (not shown). This projectile may be fuzed with a proximity fuze in its nose.

Upon firing of the proximity fuzed. projectile at a target, say, for example, an aircraft, the proximity fuze is activated and will be fired by the target, provided it passes within optimum reflection distance of the target. In some instances, the proximity fuze may not function properly, and thus the projectile will not be detonated by the said target.

In the event that the fuzed projectile fails to detonate on the target, or fails to completely arm, and other selfdestruction means built therein failed to function, the fuze 10 of the present invention will destroy the projectile.

This is accomplished by setting fuze 10 to the on- Detonation of detonator 50 thus sets off the tetryl pellets 64 and 66, which in turn detonate the tetryl booster charge 22 and explode the projectile.

As previously pointed out, when the turntable 14 is in the cit-position 26, no self-destruction action is effected.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

l. A self-destruction fuze for ordnance projectiles, comprising a housing having a base, a charge in the housing, a pellet in the base for detonating the charge, a safety unit in the base and including a turntable having a port exposed to propellent gases, a firing pin in the turntable above the port, said turntable being rotatable to armed position with the firing pin in alignment with the pallet and to unarmed position with the firing pin out of alignment with the pellet, sealing means between the firing pin and the pellet for preventing contact of propellent gases with said pellet, and means for latching the turntable in either armed or unarmed position, said firing pin in armed position being actuated by propellent gases passing through the bore for detonating the pellet and exploding the charge.

2. A self-destruction fuze for ordnance projectiles, as recited in claim 1, wherein the sealing means is constituted by a rubber gasket.

3. A self-destruction fuze for ordnance projectiles, as recited in claim 2, wherein said turntable is formed with a cavity to receive the rubber flow of said rubber gasket.

4. In combination with a self-destruction fuze having a housing provided with a base, a booster charge in the housing, a primer pellet in the base, and a firing train between the charge and the pellet; a safety unit in the base adjacent the primer pellet and including a turntable having a firing pin and a port beneath the firing pin, said firing pin being disposed in alignment with the pellet position 30 prior to firing. With the turntable 14 in the on-position 30, the gas pressure from the propellant charge activates the firing pin 34. This firing pin 34 sets off the primer charge 36, which then flames through expansion chamber 42 and ignites the igniter powder 44 and powder delay train 46 that is designed for a fixed burning time, say 28 to 30 seconds for the particular embodiment shown. However, as previously pointed out, the burning time involved will depend upon the characteristics desired in a particular self-destruction fuze. Burning through of the powder train 46 sets off an azide detonator 50.

The spin of the projectile, in the meantime, has aligned the explosive pellets 64 and 66 of rotors 56 and 58.

in armed position and being movable for igniting the pellet by fluid passing through the port, and sealing means between the turntable and the pellet.

5. The combination recited in claim 4 wherein the sealing means consists of a rubber gasket. 

